Portable rapid diagnostic test reader and methods of using the same

ABSTRACT

A portable rapid diagnostic test reader system includes a mobile phone having a camera and one or more processors contained within the mobile phone and a modular housing configured to mount to the mobile phone. The modular housing including a receptacle configured to receive a sample tray holding a rapid diagnostic test. At least one illumination source is disposed in the modular housing and located on one side of the rapid diagnostic test. An optical demagnifier is disposed in the modular housing interposed between the rapid diagnostic test and the mobile phone camera.

RELATED APPLICATIONS

This Application is a divisional of U.S. patent application Ser. No.13/485,689, filed on May 31, 2012, now U.S. Pat. No. 8,916,390, whichclaims priority to U.S. Provisional Patent Application No. 61/595,584filed on Feb. 6, 2012 and U.S. Provisional Patent Application No.61/623,212 filed on Apr. 12, 2012. Priority is claimed pursuant to 35U.S.C. § 119 and 120 and any other applicable statutes. The above-notedPatent Applications are incorporated by reference as if set forth fullyherein.

TECHNICAL FIELD

The field of the invention generally relates to devices and methods usedin connection with rapid diagnostic tests (RDTs or RDT).

BACKGROUND

RDTs are diagnostic assays designed for use at the point-of-care. RDTsare generally low cost, relatively simple to operate and read, stable ata variety of operating conditions, and work in a relatively short periodof time. Although the use of RDTs is not so limited, RDTs haveparticular application in low-resource settings where local conditionsdo not provide technology, equipment, and training for more complicatedlaboratory testing. Moreover, many patients may not reside near orcannot travel to medical sites where such testing is available.

RDTs are thus very useful tools to screen infectious diseases inresource limited settings or remote locations where conventionalapproaches (e.g., clinical examination, microscopy, etc.) are extremelylimited or even not available. Penetration of RDT technologies to publichealth endeavors has generated several advantages including, but notlimited to, better patient management where the infection symptoms arenot specific to a particular disease (i.e., asymptomatic diseases),outbreak surveillance in high-risk endemic areas, and wide-spread healthcare delivery by minimally trained technicians.

A variety of types of RDTs are in existence. These include, by way ofexample, lateral flow tests (immunochromatographic strip tests),agglutination tests, flow-through tests, and solid-phase (dipstick)assays. Lateral flow tests are one of the most common types of RDT andinclude all the reactants and detection functionality included within atest strip. In a lateral flow test, the strip is placed into a sampleand the results are read after a certain amount of time has elapsed. Anexample of a lateral flow test is commonly used home pregnancy tests. Anagglutination RDT works by observing the binding of particles to atarget analyte which is observed through the naked eye or through amicroscope. In a solid phase RDT, a dipstick is placed into contact witha sample and then washed and incubated to prevent non-specific analyteblinding. This test requires several steps such as washing and thusrequires some degree of training. These limitations can limit theusefulness of such tests in resource-limited settings. Flow throughtests obtain results quicker than lateral flow tests but require buffersolutions and additional wash steps that can limit portability andusefulness.

RDTs are used to test for the presence of infectious disease. Forexample, RDTs are used to detect HIV, malaria, syphilis, and HepatitisB. RDTs can also be used to detect other biomarkers or physicalconditions. For example, RDTs are used in making fertilitydeterminations. RDTs can also be used to test blood sugar andcholesterol levels.

Meanwhile, the current and expanding universe of wireless communicationtechnology exhibits promising potential to be utilized for powerfulwireless health applications even in the least developed parts of theworld. With more than 5 billion subscriptions worldwide, mobile phonescan be potentially used for sensing, screening and transferringubiquitous health related data using already embedded components (i.e.,CMOS/CCD sensors, LCD displays, WIFI/GSM/GPS receivers/transmitters,Bluetooth, etc.) even in field settings. Therefore, wirelesscommunication technology remains an exciting opportunity to transformthe fight against epidemics, opening new gates towards cloud-basedoutbreak monitoring platforms.

Attempts have been made at integrating mobile phones with diagnostictesting functionality. For example, Breslauer et al. have proposed abrightfield and fluorescent imaging system that includes a bulkyattachment that is used in connection with a commercially availablemobile phone. Breslauer et al., Mobile Phone Based Clinical Microscopyfor Global Health Applications, PLOS One, www.plosone.org, Vol. 4, Issue7 (2009). Smeared samples of malaria-infected cells and sickle cellanemia samples were imaged with the camera. These images were thentransferred to a separate laptop computer for automated counting ofcells. In another example, Tuijn et al. discloses a system wherebymobile phones are secured to a standard (and bulky) light microscope tocapture images on a mobile phone. These images are then transferred to acentral database for assessment, feedback, and educational purposes.Tuijn et al., Data and Image Transfer Using Mobile Phones to StrengthenMicroscopy-Based Diagnostic Services in Low and Middle Income CountryLaboratories, PLOS One, www.plosone.org, Vol. 6, Issue 12, (2011). Rocheet al. have used a camera phone for applying localized surface plasmonresonance (LSPR) label-free sensing that uses gold nanoparticles andnanorods in an assay solution contained in a in a cuvette affixed to themobile phone. Images obtained from the camera were then offloaded to aseparate computer for image processing.

SUMMARY

In one embodiment, a portable rapid diagnostic test reader systemincludes a mobile phone having a camera and one or more processorscontained within the mobile phone; a modular housing configured to mountto the mobile phone, the modular housing including a receptacleconfigured to receive a sample tray holding a rapid diagnostic test; atleast one illumination source disposed in the modular housing andlocated on one side of the rapid diagnostic test; and an opticaldemagnifier disposed in the modular housing.

In one aspect of the invention a portable rapid diagnostic test readersystem is provided that includes a mobile phone having a camera and oneor more processors contained within the mobile phone. The test readerincludes a modular housing configured to mount to the mobile phone, themodular housing including a receptacle configured to receive a sampletray holding a rapid diagnostic test. A first illumination source isdisposed in the modular housing and located on a first side of the rapiddiagnostic test while a second illumination source is disposed in themodular housing and located a second, opposing side of the rapiddiagnostic test. An optical demagnifier is disposed in the modularhousing. A switch is provided to selectively illuminate the rapiddiagnostic test with either the first illumination source or the secondillumination source.

In another embodiment, a method of reading a rapid diagnostic test usinga mobile phone having camera functionality includes securing a rapiddiagnostic test reader to the mobile phone. The rapid diagnostic test isinserted into the reader. The rapid diagnostic test is illuminated withillumination from one or more of the illumination sources. An image ofthe rapid diagnostic test is captured with the camera of the mobilephone. The captured image is processed with at least one processor andoutputting a test result to the user based at least in part on theprocessed image.

A method of monitoring a pathological condition over an extendedgeographical area using RDT results obtained from a plurality of mobilephones includes receiving a plurality of RDT reports from the pluralityof mobile phones at a computer that is remotely located from theplurality of mobile phones; storing the RDT reports in a database;receiving a query of the RDT reports contained in the database from aremote location; and returning query results to the remote locationwhere the query is made.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B illustrate a view of an exemplary lateral flow RDTusable in connection with the test reader.

FIG. 2A is a side schematic representation of a portable RDT readersystem according to one embodiment.

FIG. 2B is a cross-sectional view taken along the line A-A′ with thesample tray and RDT loaded into the test reader.

FIG. 3 is a partial perspective view of one embodiment of a RDT readerwith portions of the housing removed so as to illustrate variousinterior components of the RDT reader.

FIG. 4A is a side view of a portable RDT reader system according toanother embodiment.

FIG. 4B is a partial perspective view of another embodiment of a RDTreader with portions of the housing removed so as to illustrate variousinterior components of the RDT reader.

FIG. 5 is a schematic representation of a system that integratesmultiple portable RDT readers.

FIG. 6 illustrates an exemplary automated image analysis process fordetermining whether a RDT is valid/invalid and positive/negative.

FIG. 7A illustrates a user login screen on a mobile phone that is usedto access the RDT application.

FIG. 7B illustrates an illustrative user menu presented to the user of amobile phone running the RDT application.

FIG. 7C illustrates an exemplary menu that prompts a user to select froma list of pre-programmed RDTs.

FIG. 7D illustrates a raw image of the RDT captured by the camera of themobile phone.

FIG. 7E illustrates an exemplary diagnosis form that is presented to auser on a mobile phone. The diagnosis form indicates whether the testwas valid or invalid and whether the test was positive or negative. Theform also includes options for the user to provide user-specificinformation that will be associated with the test result.

FIG. 7F illustrates a map showing the location of several RDTs (e.g.,positive tests) that is displayed to a user on a mobile phone.

FIG. 7G illustrates an antigen quantification screen that is displayedon a mobile phone device.

FIG. 8A illustrates the acquired image of the HIV 1/2 Ab PLUS Combo RDTobtained from the camera of a mobile phone. Also illustrated below theraw image is the processed image showing that the sample is valid andnegative.

FIG. 8B illustrates the acquired image of the TB (IgG/IgM) RDT obtainedfrom the camera of a mobile phone. Also illustrated below the raw imageis the processed image showing that the sample is valid and negative.

FIG. 8C illustrates the acquired image of the Optimal-IT Malaria(Pf/Pan) RDT obtained from the camera of a mobile phone. Alsoillustrated below the raw image is the processed image showing that thesample is valid and negative.

FIG. 8D illustrates the acquired image of the Optimal-IT Malaria(Pf/Pan) RDT loaded with a positive sample obtained from the camera of amobile phone. Also illustrated below the raw image is the processedimage showing that the sample is valid and positive (showing two bandsin addition to control band).

FIG. 8E illustrates the acquired image of the Optimal-IT Malaria(Pf/Pan) RDT loaded with a highly diluted sample obtained from thecamera of a mobile phone. Also illustrated below the raw image is theprocessed image showing that the sample is valid and positive (showingtwo feint bands in addition to control band). The feint bands are causedthe low antigen density that resulted from the dilution process.

FIG. 9 illustrates a graph of color intensity of a Optimal-IT Malaria(Pf/Pan) RDT test strip subject to varying dilutions levels (1×, 2×, and3×). Inset in the graph are respective strip test images of the variousdilution tests.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIGS. 1A and 1B illustrate one type of rapid diagnostic test (RDT) 10.The RDT 10 illustrated in FIGS. 1A and 1B is a so-called lateral flowRDT 10 whereby capillary flow of liquid is used to move a sample anddye-labeled antibody specific to target antigen(s) across a substratelike a nitrocellulose strip. The RDT 10 may include a housing 12 that istypically a rigid support substrate or holder that contains therein atest strip 14. The housing 12 may include one or more ports 16 intowhich a sample or other solutions are loaded into the RDT 10. The teststrip 14 may include a nitro-cellulose strip that contains dye-labeledantibody 18 along a portion thereof that is carried down the length ofthe test strip 14 when a sample is loaded into the RDT 10. Thedye-labeled antibody 18 may, in some embodiments, include one or morefluorescent dyes, molecules, or quantum dots making the RDT 10 afluorescent RDT 10. The test strip 14 includes a test band 20 thattypically consists of bound antibody bound to the test strip 14 along athin test line. Also included on the test strip 14 is a control band 22that includes bound antibody or antigen. It should be noted that in FIG.1A, the test band 20 and the control band 22 are not normally visibleprior to the depositing a sample on the RDT 10.

During use, a sample is loaded into the RDT 10, for example, by placinga sample in the port 16. The sample, may include any number ofbiological fluids including, for instance, blood, serum, plasma, sputum,and the like. The sample may even include other non-biological sourcessuch as a water sample. After the sample has been loaded onto the RDT10, the sample as well as the dye-labeled antibody 18 are drawn acrossthe test strip 14 in the direction of arrow A. If the target antigen ispresent in the sample, some of the labeled antigen-antibody complex willbe trapped on the test band 20. Excess labeled antibody is trapped onthe control band 22. Often, colloidal gold is used to form gold-labeledantibody-antigen complexes that can then be visualized although the useof colloidal gold is not necessary with the concepts described herein.

While FIGS. 1A and 1B illustrate a test band 20 and a control band 22,the testing location and the control location may take other forms otherthan a band or line. For example, the testing location on the test strip14 may take the form of a dot or other geometric shape. The same applieswith respect to the control location on the test strip 14. Similarly, asingle test strip 14 may contain multiple test sites and multiplecontrol sites. For example, a single test strip 14 may test for thepresence of multiple antigens. FIGS. 1A and 1B illustrate one type ofRDT 10 that is usable in connection with the test reader describedherein but it should be understood that other types of RDTs 10 may beuseable in connection with the test reader. These include other formatslike dipsticks, cassettes, strips, cards, pads or the like. Moreover,the test reader is usable with various RDT formats beyond lateral flowRDTs such as, for example, agglutination tests, flow-through tests, andsolid-phase (dipstick) assays. What is common amongst all thesedifferent types of RDT formats is that there is a test location andcontrol location that is capable of spectrographic interrogation andvisualization.

FIG. 2A schematically illustrates, in exploded format, a portable rapiddiagnostic test reader system 30 according to one embodiment. The system30 includes a mobile phone 32 that includes a camera 34 therein. In thisregard, the camera 34 of the mobile phone 32 typically includes animaging sensor 36 and a lens 38. The mobile phone 32 includes thereinone or more processors 40 that are used to run software of the mobilephone 32 as well as communicate voice and data wirelessly to basestations (not shown) as part of a communications network. As describedin more detail below, the processor(s) 40 of the mobile phone 32 areutilized, in one embodiment, to process and analyze captured images fromthe test reader. Thus, in this embodiment, the mobile phone 32 includessoftware loaded thereon for image processing. This software may beloaded in the memory (not illustrated) in the mobile phone 32 and mayappear on the mobile phone 32 as an application or “app” which can thenbe run during testing. The application may be usable with a wide varietyof operating systems including, but not limited to, ANDROID and IPHONE,operating systems. This software is executed or otherwise run on theprocessor(s) 40 of the mobile phone 32. In other embodiments, asexplained below, image processing may take place in a remote locationaway from the mobile phone 32.

The mobile phone 32 may also include global positioning satellite (GPS)functionality for location-based services. GPS may be integrated intothe processor(s) 40 described above or may be implemented with adedicated GPS processor 42 or as integrated as part of theradiofrequency electronics of the mobile phone 32. The mobile phone 32includes a battery 44, which in certain embodiments, is used to powerthe test reader as explained in detail below. The mobile phone 32includes a display 46 that displays information to the user. These maybe prompts and input fields for the user running the rapid diagnostictest or they may include test result information, image data,epidemiology information, geographical information, and the like. Themobile phone 32 illustrated in FIG. 2A includes an audio jack 48. In oneembodiment, the audio jack 48 may be used as a switch to modulatebetween a transmission mode and a reflective mode for the test reader.The system 30 described herein is usable with any number of mobilephones 32 from any number of manufacturers (e.g., SAMSUNG, HTC, APPLE,NOKIA, MOTOROLA, and the like). These include so-called “smart phones”that generally have more features and functionality (and higher cost)than other mobile phones 32 as well as mobile phones 32 with lessfeatures. All that is required, is the ability of the mobile phone 32 tohave camera functionality and communicate wirelessly over a network(e.g., GSM, CDMA, WiFi, Bluetooth, and the like). In this regard, insome embodiments, the mobile phone 32 may actually be more of a portableelectronic device as opposed to a phone. For example, a portableelectronic device that has camera functionality along with the abilityto communicate wirelessly over a WiFi network can carry out many of theaspects described herein.

Still referring to FIG. 2A, the system 30 includes a RDT test reader 50that is configured to be removably attached to the mobile phone 32. Thetest reader 50 is generally compact such that when secured to the mobilephone 32, the combined apparatus is still hand-held. Generally, the testreader 50 has volume of less than about 500 cm³ and weighs less than 300grams (excluding batteries). The test reader 50 is configured todetachably mount to the face of the mobile phone 32 having the camera 34thereon. As explained herein, the test reader includes a housing 52 thatincludes one or more contact points that engage with the outer body ofthe mobile phone 32 thereby allowing the test reader 50 to be affixed tothe mobile phone 32. For example, the housing 52 may configured toengage the outer edges of the mobile phone 32 using tabs 53 (as seen inFIG. 2B) that flexibly engage the mobile phone 32. The housing 52 mayhave any number of geometries and configurations such that the testreader 50 can be attached to a wide variety of makes and models ofmobile phones 32. The housing 52 is able to secure to the mobile phone32 and substantially blocks out ambient light. Thus, rather thancapturing images of RDTs 10 using room light or sunlight, the housing 52includes its own illumination sources as described herein. Moreover, thehousing 52 can be accurately placed on the mobile phone 32 to provide auniform optical path between the illumination sources and the mobilephone camera 34. This increases measurement repeatability and voidsreading errors due to illumination and field-of-view variations ortilts, all of which are substantially eliminated with the designsdisclosed herein.

The test reader 50 includes a sample tray 54 that is dimensioned to holda RDT 10 therein. The sample tray 54 may be dimensioned or otherwiseconfigured with a particular RDT 10. For example, a sample tray 54 of afirst type may be used to hold a RDT 10 for malaria from manufacturerABC. A second, different sample tray 54 of a second type may be used tohold a RDT 10 for malaria from a different manufacturer. In this regard,the test reader 50 may be provided, in some embodiments, with a varietyof different sample trays 54 with different sample trays 54 designed tohold different RDTs 10. For example, a kit may be provided that includesa test reader 50, multiple different sample trays 54, as well asinstructions for use. The outer dimensions of the sample tray 54 aregenerally uniform across different RDTs 10 thus permitting the differentsample trays 54 to be universally used in the same test reader 50. Thesample tray 54 is configured to be inserted (in direction of arrow A)into the housing 52 of the test reader 50. The housing 52 may include areceptacle 51 therein that is dimensioned to hold the sample tray 54 ata fixed location therein such that the relevant portions of the RDT 10can be imaged by the camera 34 of the mobile phone 32. The sample tray54 may be reusable or, in other embodiments, may be disposable.

In one optional aspect, the housing 52 of the test reader 50 includes aposition sensor 56 that is able to detect when the sample tray 54 hasbeen properly inserted into the housing 52. For example, the sensor 56may lock-out or prevent the illumination sources (described below) fromactuating until the sample tray 54 has been properly inserted.Alternatively, the sensor 56 may be coupled to an indicator 58 such as alight or the like that indicates to the user that the sample tray 54 hasbeen properly inserted into the test reader 50.

Still referring to FIG. 2A, the test reader 50 includes a firstillumination source 60 that is disposed in the housing 52 so as to placethe illumination source 60 on one side of the RDT 10. The firstillumination source 60 is used as a transmission light source wherebylight passes through the testing location of the RDT 10 (e.g., teststrip 14). The first illumination source 60 may include one or moreLEDs. In one particular embodiment, the first illumination source 60 mayinclude an array of diffused LEDs (e.g., 754-1185-5-ND, Digi-key, USA).The test reader 50 further includes a second illumination source 62 thatis located on an opposing side of the RDT 10 when loaded within the testreader 50. The second illumination source 62 is used as a reflectionlight source whereby light reflects off the testing location of the RDT10. In one aspect, the second illumination source 62 includes first andsecond diffused LED arrays 62 a, 62 b (as seen in FIG. 2B) that arelocated underneath the plane of the RDT 10. As seen in FIG. 2B, thefirst diffused LED array 62 a and the second diffused LED array 62 b areangled and located outside the optical path to the camera 34 to ensureuniform illumination of the target test site. The particular wavelengthof the first illumination source 60 and the second illumination source62 can be tuned to best match the appropriate RDT 10. For example, ithas been experimentally determined that LEDs with a peak wavelength of565 nm achieves high contrast for both control and test lines formalaria RDTs that utilize colloidal gold. Of course, the illuminationwavelength can be changed or tuned depending on the particular RDT 10.In one aspect, the test reader 50 may include the ability to modulate oradjust the particular wavelength(s) of light emitted from the first andsecond illumination sources 60, 62.

Reflection mode is practical and useful for most test formats includingcassette-type RDTs 10 which have a plastic housing protecting a lateralflow pad with a window on one side as well as strip tests without anyprotective housing. Transmission mode is useful for strip-based RDTs 10.In order to give the user flexibility on whether to image intransmission or reflection mode a switch 64 is provided that togglesbetween transmission mode and reflection mode. In transmission mode,only the first illumination source 60 is activated during imaging. Inreflection mode, only the second illumination source 62 is activatedduring imaging. In an alternative embodiment, instead of placing theswitch 64 on the housing 52, the switch may be inserted into the audiojack 48 of the mobile phone 32.

In an alternative embodiment, the test reader 50 may only have oneillumination source with no switching functionality. For example, thetest reader 50 may include only the first illumination source 60 suchthat it operates exclusively in a transmission mode. Alternatively, thetest reader 50 may have only the second illumination source 62 such thatit operates exclusively in reflection mode.

To power the test reader 50, a battery 66 is provided in the housing 52.The test reader 50 does not have significant power requirements and maybe powered by two AAA batteries although other battery types are alsocontemplated. In another embodiment, as illustrated in FIGS. 4A and 4B,rather than using one or more batteries 66, the battery 44 of the mobilephone 32 is used to power first and second illumination sources 60, 62,respectively. In this embodiment, a USB dongle or cable 72 connects themobile phone 32 to the test reader 50 to provide power.

Referring to FIGS. 2A and 2B, the test reader 50 includes an opticaldemagnifier 68 that is used to demagnify the image. Rather thanmagnifying the area that is to be imaged, the test reader 50 needs tosee a larger field of view. For this reason, an optical demagnifier 68is interposed between the test plane of the RDT 10 and the camera 34 ofthe mobile phone 32. In one aspect, the optical demagnifier 68 is a lens(e.g., plano-convex lens with a focal length of less than about 20 mm).The optical demagnifier 68 has a demagnification factor that is withinthe range of between about 1 and about 50.

This demagnification factor can be tuned, if needed, by changing thefocal length of the external lens of the test reader 50. Note that fordigital image processing of the RDT results on the mobile phone 32, thisoptical demagnification factor together with the pixel size of the CMOSimager (e.g., ˜1-2 μm) are the key factors to effect spatial sampling ofRDT test lines. As expected, the overall magnification of the system,which also depends on the mobile phone 32 display size is not relevantfor automated analysis of RDT results.

With reference to FIGS. 2A and 2B, in one alternative embodiment, thetest reader 50 includes an optional color filter 70. The color filter 70may be used for fluorescent RDTs 10. In this embodiment, one or both ofthe first illumination source 60 and/or the second illumination source62 can be used as fluorescent excitation sources. The optional colorfilter 70 is used to reject the excitation light provided by thesesources but permit the passage of the emitted fluorescent light suchthat it can then be read by the camera 34 on the mobile phone 32. Thecolor filter 70 may be optionally removable from the housing 52 of thetest reader 50. In this regard, the test reader 50 can be used with bothfluorescent and non-fluorescent RDTs 10.

FIG. 3 reveals a perspective view of a test reader 50 according to oneembodiment. The test reader 50 is similar to that illustrated in FIGS.2A and 2B. The test reader 50 of FIG. 3 is light-weight, weighing around65 grams (excluding batteries). The width (W) of the test reader 50 isless than about 80 mm and has a length (L) of less than about 40 mm. Theheight (H) of the test reader 50 is less than about 50 mm. Of course,dimensions outside the ranges specifically mentioned above arenonetheless contemplated to fall within the scope of the inventionprovided the unit remains hand-held. The housing 52 may be made from apolymer material giving the same structural integrity while at the sametime imparting some flexibility to the tabs 53 or other affixationpoints (e.g., tabs 53) so that the test reader 50 can be secured to themobile phone 32 (now shown in FIG. 3).

FIGS. 4A-4B illustrate another embodiment of a portable rapid diagnostictest reader system 30. In this embodiment, a cable 72 such as a USBcable connects the mobile phone 32 to the test reader 50. In this way,the battery 44 from the mobile phone 32 is used to power allfunctionality of the test reader 50. Power is transmitted through thecable 72 and powers the first illumination source 60 and the secondillumination source 62 (seen in FIG. 4B). In addition, in thisembodiment, a tray sensor 74 is disposed in the housing 52 of the testreader 50 to detect whether the sample tray 54 containing the RDT 10 isproperly loaded into the test reader 50 and ready to be imaged. Thisembodiment also uses a low cost processor 76 (e.g., micro-controller)that interfaces with the tray sensor 74 and controls two (2) visualindicators 78, 80 to alert the user that (i) the sample tray 54 isproperly loaded into the test reader 50 and ready to be imaged and (ii)whether the test reader 50 is properly powered through the battery 44 ofthe mobile phone 32.

FIG. 4B illustrates a perspective view of the test reader 50 withvarious surfaces in phantom or removed so as to show various internalcomponents of the test reader. FIG. 4B illustrates the firstillumination source 60 used for testing the RDT 10 in the transmissionmode. Also illustrated is the second illumination source 62, which mayagain be formed from two separate LED arrays, located on an opposingside of the sample tray 54. The second illumination source 62 is usedfor reflection mode testing. FIG. 4B illustrates an optical demagnifier68 in the form of a lens disposed in the housing 52 of the test reader50.

As stated above, the mobile phone 32 contains a software applicationthat digitally records images of the RDT 10 and, in one embodiment,rapidly evaluates the test results. The software application isexecuted, in one embodiment, using the one or more processors 40contained in the mobile phone 32. Preferably, test results can beobtained within a short period of time such as within a few seconds.Once the image is captured using the test reader 50 attached to themobile phone 32, the application stored on the mobile phone 32 thenprocesses the image to generate a test result to the user. The testresult includes at least two pieces of information: (1) a determinationwhether the test is valid or invalid, and (2) a determination whetherthe test is positive or negative. Optionally, a test report whichincludes additional information may also be generated by theapplication. The test report includes test result information inaddition to information such as, patient-specific information (e.g.,age, sex, medical history information), time-stamp, geographic locationof where test conducted, geographic location of where tested individualis located, test image, disease type, (e.g., identification of disease),and test type data (e.g., manufacturer of test and other information).Geographic location may be automatically determined based on GPSlocations generated, for example, by the GPS processor 42. Time-stampdata may be obtained using the date and time of the mobile phone 32 orthe network on which such device runs. Using the wireless functionalityof the mobile phone 32 (or other mobile electronic device), the sameapplication that generates the test result and/or test report uploadsthe data to a remote server 90 that contains a database of plurality oftest results of different users as illustrated in FIG. 5. A variety ofdifferent wireless protocols may be used to transmit the data includingWiFi, GSM, CDMA, and the like. The data is transmitted across a network92 that may include a proprietary network or an open network such as theInternet. The amount of data that is transferred is typically fairly lowand is generally less than about 0.05 Mbytes per test. Data may also betransferred using the Short Message Service (SMS) functionality of themobile phone 32. The application running on the mobile phone 32 maytemporality store the test result on the mobile phone 32 if, forexample, there is not sufficient wireless coverage or connection to theremote server 90 has been interrupted. The data can then be transmittedautomatically to the remote server 90 once the connection has beenre-established or manually transmitted by the user.

Still referring to FIG. 5, in one aspect, a personal computer 94 is ableto access the database contained in the remote server 90. Using astandard web interface, a user of the personal computer 94 can query thedatabase of the remote server 90 and display RDT data in a variety ofdifferent formats. For example, the user may display RDT data that isoverlaid on top of a map. In such a case the display 96 of the personalcomputer 94 may illustrate a map of a particular geographic region withall the positive RDTs being displayed on the map at their respectivegeographical locations. This feature may be particularly use from anepidemiological standpoint such that disease progression and outbreakscan be monitored remotely. For example, the system 30 described hereinmay be used to develop and monitor a real-time infection map that showsthe location of persons infected with a particular disease.

By having multiple mobile phones 32 equipped or otherwise used inconnection with test readers 50 that communicate with a central databaseon a remote server 90, infectious diseases can be monitored and trackedacross an extended geographical area. RDT results obtained from aplurality of mobile phones where they are transmitted and received atthe remote server 90. Test reports received at the remote server 90 arestored in a database. The remote server 90 can then receivequeries—either from the mobile phones 32 or from other computersconnected to the remote server. Query results are returned to the remotelocation where the query is made.

In addition, the user can selectively filter data from the remote server90 to display only the results of interest. For example, a user canfilter based on a variety of attributes including disease type, testlocation, date, time, RDT type/manufacturer, patient age, sex, and thelike. While FIG. 5 illustrates both personal computers 94 and mobilephones 32 that can access and query the database of the remote server 90it should be understood that other electronic devices having web browserfunctionality may also be used for this purpose.

FIG. 5 illustrates an exemplary data header 94 of an example data packetthat is transmitted from the mobile phone 32 to the remote server 90over a network 92. The data header 94 may include determination of validor invalid test; test result (i.e., positive or negative), sex, age,location (e.g., longitudinal and latitude coordinates), test type date,and strip image data. FIG. 5 also illustrates an example of a datapacket 96 that is transmitted from the mobile phone 32 over the network92 to the remote server 90. In this example, the data packet 96 concernsa valid test from a male subject age 29 that tested positive for the HIVvirus. The data packet 96 further includes location data (longitude andlatitude coordinates) and an image of the strip. It should be understoodthat the data packet 96 is exemplary and more or less information may becontained in the same.

The RDT images that are uploaded to the remote server 90 can also serveto identify possible duplicate uploads of the same test. This is done byexamining the pixel values of the uploaded images. Once identified asthe same test image, duplicate entries can be deleted or merged at theserver side by, for example, an authorized superuser/root.

With reference now to FIG. 6, the software stored on the mobile phone 32automatically processes the raw images obtained of the RDT 10 using thesystem 30. The images may be obtained either in transmission mode orreflection mode. In operation 500, raw images are acquired using thecamera 34. One such image is illustrated just adjacent to operation 500.These raw images obtained in operation 500 are then subject to pixelmatrix generation in operation 510 wherein the image is then convertedfrom 3 channel YUV420 scale to grayscale as seen in operation 520. Thegrayscale image is seen just below operation 520. In the images seen inFIG. 6, there are three (3) lines or bands appearing in the images. Oneline (the left most) in FIG. 6 represents the control line while theremaining two lines of FIG. 6 represent test lines. After the conversionto grayscale in operation 520, the image is enhanced in operation 530.All (3) three lines thus appear with greater clarity. In the nextoperation 540, the region(s) of interest are then extracted from thetest strip 14. For example, as seen in the graph in operation 540 thethree main regions of interest correspond to the image portionsrevealing the control line and two test lines. Extraction of theregion(s) of interest can be accomplished by segmentation of thenon-functionalized background as seen in operation 550. In thisoperation, the “background” portions of the image are identified.Correspondingly, segmentation of the functionalizedimmunochromatographic regions (i.e., the control and test regions) areidentified as seen in operation 560. For example, initially theboundaries of the RDT lateral flow area are found, and the flow area isclipped out from the rest of the image.

Once the control and test regions are isolated and extracted, aquantitative determination is made of the RDT test evaluation todetermine whether the test is valid or invalid as seen in operation 570.This is made be evaluating the extracted image region corresponding tothe control region and comparing or thresholding this region todetermine whether the RDT 10 is valid or invalid. Similarly, theextracted image regions corresponding to the test lines or test bandsare compared or thresholded to determine whether the particular sampletested was positive or negative. In the example of FIG. 5, the samplewas tested for PAN malaria infection and PF malaria infection. Both testlines are such that a positive determination is mode for both antigentypes. While FIG. 6 illustrates one illustrative manner of imageprocessing, it should be understood that other image processingalgorithms and processes could be used to achieve the same result. Aperson of ordinary skill in the art could use a variety of differentimage processing techniques to isolate and evaluate the control and testlines that appear in raw images obtained from the camera 34 of themobile phone 32.

In one particular embodiment, after the boundaries of the RDT 10 flowarea are found and clipped out from the rest of the image, the averagecolumn pixel intensity per row is obtained, such that if the originalgrayscale image is a [R, C] matrix, one ends up with a [R, 1] columnvector, with each element in the vector being the average value of thepixels in the corresponding row of the grayscale (single channel) image.Next, in the case of Optimal-IT Malaria RDT, the maximum value of theaverage column pixel intensity per row vector is taken and every pixelthat is less than 90% of this value is zeroed in order to remove theparts of the image which do not carry any useful information such as thebackground. This leaves one with only non-zero values for pixels thatare part of the RDT test strip 14 itself. The original grayscale imageis taken and cropped by a rectangle that starts and ends at the rowswhere the threshold vector is non-zero. The strip stretches across theentire width of the image, so that the cropped rectangle has an equalamount of columns as the acquired image. The image is then saved to theprivate file-space of the mobile phone 32, to be uploaded to a serverfor data mining.

In the case of the CTK TB (Tuberculosis) and HIV RDTs (HIV 1/2 Ab PLUSCombo Rapid Tests and TBIgG/IgM Combo Rapid Tests, CTK Biotech Inc., CA,USA), the [R,1] average column pixel intensity per row vector isobtained from the image after first discarding 20% of the columns takenfrom both ends to avoid spatial artifacts. Then, the absolute value ofthe derivative of the average column pixel intensity per row vector iscalculated to locate the rows that the strip lies on. Because of theacceleration in pixel values as one goes down the rows of the image,they occur right before and right after the target flow area. Theoriginal grayscale image is then digitally cropped across theappropriate rows, and finally saved to the private file-space of themobile phone 32, to later be uploaded to a server for data mining.

Once the flow areas of the RDTs 10 are obtained, they are processed toget the locations of the control and infection lines. This is done byfirst creating a row vector obtained by averaging the pixel values alongthe columns of the image of flow areas. The local maxima of the rowvector indicate the positions of the lines. To better handle detectionnoise and spatial non-uniformities on the RDT 10, a central movingaveraging operation is also performed on the row vectors to get rid ofhigh-frequency spatial noise. Since the lighting of the strip may notalways be 100% uniform, the vector is subtracted from its convex hull.Then the highest peak is found and anything less than 10% of it iszeroed out.

For the final decision, first the presence of a control line is checkedat the location where it is presumed to be. If it is present, the testis valid, and otherwise it is labeled as an invalid test. If the test isvalid, the locations of the infection-indicating lines are then checkedto determine the result of the test (i.e., positive or negative). Notethat for different RDT 10 types, from various manufacturers, minormodifications of the above discussed processing flow could be needed tohandle variations in the design and packaging of different types oftests

FIGS. 7A-7G illustrate various user prompts, input screens, andinformation that is presented to the user of the system 30 according toone embodiment. As seen in FIG. 7A, the application running on themobile phone 32 starts with a login screen where the user fills in theform with his or her credentials to thereby create a HTTP POST to theserver 90. The server 90 verifies the authenticity of the user and findsthe user in the database and returns the necessary cookie files withtheir user information. The server 90 may run using a MySQL 2 databaserunning RoR or Rails. As seen in FIG. 7B, the user is presented with anapplication menu where the user can analyze new diagnostic tests, browsethrough a real-time database of tests (e.g., SQLite) or set thepreferences for the application. If the user selects to image a newtest, a pull-down menu of pre-configured RDT test is presented to theuser and the user can then browse and select the appropriate test kit asseen in FIG. 7C. The software may be updated as new RDTs are developedor become available.

When the user decides on a new test to be evaluated, the mobile phoneapplication accesses and powers on the back facing camera of the phoneand the user decides whether they want to turn on the transmission orreflection illumination LED arrays (i.e., first illumination source 60or second illumination source 62). When the test reader 50 is all theway in the housing 52 (for example, as determined by position sensor56), the application starts grabbing frames from the camera 34 anddisplays them on the display 46 of the mobile phone 32. If the userwants to diagnose the RDT 10, the user touches the screen (or otherinput device such as button) to capture an image of the RDT 10 to beanalyzed. FIG. 7D illustrates a raw image taken of the RDT 10.

The digitally captured RDT image is then converted into a grayscalematrix which is analyzed by an identification algorithm such as thatillustrated in FIG. 6 to determine the type of test being captured,unless the user has already specified its type. Once the test type isdetermined, the mobile phone 32 analyses the grayscale matrix for testfeatures (i.e., control and test lines, test bands, test dots, and thelike) specific for this particular test type. After extracting anddiagnosing test features, the application displays an evaluation form asseen in FIG. 7E including an automatically generated test report(Valid/Invalid and Negative/Positive) as well as patient age, sex,additional comments/information, etc. which can be manually entered. Theuser can then decide to upload the completed form and the processedimage of the RDT 10 to the server 90, or save it onto the mobile phone'slocal memory for transmission later on. If the results are sent to theserver 90, the server 90 checks the credentials of the user and savesthe new data into its database.

The user can also reach the real-time RDT monitoring database running onthe local server and browse through a global map of previously uploadedtest results. The server displays the test data on an internet browserusing commercially available mapping applications (e.g., Google Maps)and can filter the data displayed based on several attributes,including: disease type, test location and time/date, RDTtype/manufacturer, patient age, etc. The users can access this real-timemonitoring platform through the same mobile phone 32 as seen in themobile phone display image seen in FIG. 7F or using a personal computer94 (as seen in FIG. 5) with internet connection. The same mobile phone32 running the application contained thereon can quantify the test linecolor intensity which can then be correlated to the level of antigendensity. That is to say that line color intensity may be correlated withthe density of the particular target molecule, protein, and antigen.

Experimental Results

The performance of the mobile phone-based RDT reader was validated byimaging several lateral flow based RDTs including Optimal-IT P.falciparum-specific and Pan-specific Malaria Tests (Bio-RadLaboratories, Inc., CA, USA), HIV 1/2 Ab PLUS Combo Rapid Tests as wellas TB IgG/IgM Combo Rapid Tests (CTK Biotech Inc., CA, USA). In order toactivate malaria tests, OptiMAL positive control wells (Bio-RadLaboratories, Inc., CA, USA) were used containing recombinant antigens(LDH) of P. falciparum.

Following the manufacturer's instructions, Malaria, HIV and TB RDTs weretested using whole blood samples. Prior to imaging experiments, testresults were verified by visual inspection, and the mobile phone-basedimaging experiments were repeated more than 10 times in order tovalidate repeatability of measurements. Although some lateral flowartifacts were visually observed in some cases, the RDT readerapplication provided the correct results in all tests. FIG. 8Aillustrates the raw acquired image of the HIV 1/2 Combo RDT along withdigitally processed reflection images of the RFTs which are activated byfresh whole blood samples. Also indicated in FIG. 8A is the automateddecisions (e.g., valid/negative) made by the application running on themobile phone 32. As seen in FIG. 8A, there is a control reagent lineindicating the validity of the test, and two pre-deposited antigen(HIV-1 and HIV-2) coated lines indicating the infections. FIG. 8Billustrates the raw acquired image of the TB IgG/IgM Combo RDT alongwith digitally processed reflection images of the RFTs which areactivated by fresh whole blood samples. TB IgG/IgM Combo RDT is also alateral-flow based immunoassay for simultaneous detection anddifferentiation of IgM anti-Mycobacterium Tuberculosis (M.TB) and IgGanti-M.TB in human serum or whole blood (shown in raw images as M and G,respectively). Also indicated in FIG. 8B is the automated decisions(e.g., valid/negative) made by the application running on the mobilephone 32. The control line is present with no line at either the M or Grow indicating a valid, negative test.

Malaria RDTs were also tested using OptiMAL positive control wells whichcontain recombinant antigens (LDH) of P. falciparum. These tests wereactivated based on the instructions provided by the manufacturer, and P.falciparum-specific as well as Pan-specific (P. Falciparum, P. Vivax, P.Ovale and P. malariae) reagent lines were clearly observed and evaluatedas positive by the RDT application running on the mobile phone. FIGS.8C-8E illustrate the raw acquired reflection image of the OptiMAL RDTalong with digitally processed reflection images of the RFTs which areactivated by blood. FIG. 8C illustrates a valid, negative test asevidenced by the presence of the control line but no other test linesthat detect Plasmodium antigens (pLDH) using monoclonal antibodies. FIG.8D illustrates a valid, positive OptiMAL RDT as evidenced by thepresence of the control line plus two test lines. In the test of FIG.8D, positive control wells were used which were previously coated byrecombinant antigens of P. falciparum.

To further shed light on the performance of the mobile phone-based RDTreader shown, highly diluted positive control samples were imaged andautomatically evaluated using Optimal-IT P. falciparum and Pan-MalariaRDT. FIG. 8E illustrates valid, positive OptiMAL RDT as evidenced by thepresence of the control line plus two feint test lines. This, despitethe samples being diluted beyond manufacturer recommendations.Pan-Malaria specific antigens that are previously deposited inside thecontrol wells were released by mixing with sample diluents provided bythe manufacturer. The experiments were started with an initialconcentration of Positive Control Well Antigen (PCWA)/20 μl, which isthe “recommended” dilution level by the manufacturer. Next we diluted itby 2, 3, and 4 times to create lower concentration levels of PCWA/40 μl(2× dilution), PCWA/60 μl (3× dilution), and PCWA/80 μl (4× dilution),respectively.

Ten (10) RDT measurements for each one of these concentration levels(i.e., 40 measurements total) were made. In these experiments, themobile phone platform correctly analyzed (yielding valid & positiveresults) all the Malaria RDTs that were activated with PCWA/20 μl,PCWA/40 μl as well as PCWA/60 μl. However, the accuracy decreased to˜60% for PCWA/80 μl (i.e., at 4× lower concentration compared to thesuggested dilution level) which is due to the low antigen density andthe corresponding weak color intensity. FIG. 9 illustrates the averagecross-sectional intensity profiles of these RDT strips for PCWA/20 μl,PCWA/40 μl as well as PCWA/60 μl. In these results, it is important toemphasize that the cross-sectional intensity of the control line has nocorrelation with the density of the malaria antigens as it indicatesonly the validity of the RDT. On the other hand, a higher averageintensity on P. Falciparum infection line was observed as compared tothe average intensity of the Pan-Malaria infection line for all theconcentration levels. This is expected since P. Falciparum lines werepre-deposited by only P. Falciparum specific antibodies, whereasPan-malaria lines are specific to all four kinds of Plasmodium (Malaria)species (P. falciparum, P.vivax, P.ovale and P.malariae), exhibitingweaker response compared to the P. Falciparum test line. These resultshighlight the sensitivity of the platform to differentiate such minorvariations (in response to analytes) which are quite difficult toobserve and quantify during visual examination of RDTs by humans,especially under varying illumination and imaging conditions that mightoccur in field conditions.

While embodiments have been shown and described, various modificationsmay be made without departing from the scope of the inventive conceptsdisclosed herein. The invention(s), therefore, should not be limited,except to the following claims, and their equivalents.

What is claimed is:
 1. A method of reading a rapid diagnostic testloaded with a sample using a mobile phone or other portable electronicdevice having camera functionality comprising: removably securing aseparate hand-held rapid diagnostic test reader to the mobile phone orother portable electronic device, the rapid diagnostic test readerweighing less than 300 grams and including both a transmissionillumination source and a reflection illumination source; inserting therapid diagnostic test into the reader, the rapid diagnostic testcomprising a test location and a control location; selecting one of thetransmission illumination source and the reflection illumination source;illuminating the rapid diagnostic test with illumination from theselected illumination source; capturing an image of the test locationand control location with the camera of the mobile phone or otherportable electronic device; and processing the captured image with imageprocessing software executed by at least one processor, the imageprocessing software converting the captured image to grayscale andextracting regions of interest from the test location and the controllocation in the grayscale image of the field of view, the imageprocessing software and compares respective measured intensity values ofthe regions of interest with respective intensity threshold values andoutputting a test result for the sample to the user based at least inpart on the comparisons, the test result comprising a positive/negativeindication as well as a validity indication.
 2. The method of claim 1,wherein the captured image is processed using one or more processorscontained in the mobile phone or other portable electronic device. 3.The method of claim 1, further comprising transferring the test resultto a database at a remote location.
 4. The method of claim 1, whereinthe captured image is transmitted to a remote location using anapplication or software program running on the mobile phone or otherportable electronic device and wherein said processing occurs at theremote location.
 5. The method of claim 4, further comprising returningthe test result(s) to the application or software program running on themobile phone or other portable electronic device via wirelesstelecommunication.
 6. The method of claim 1, further comprisingtransmitting the captured image along with a test report to a remotecomputer.
 7. The method of claim 6, wherein the test report comprises atest validity indication, image data, and user-input data.
 8. The methodof claim 7, wherein the test report comprises geographical location andtime-stamp data.
 9. The method of claim 6, further comprising queryingof test results a remotely located database connected to the remotecomputer, the database containing a plurality of test results, andreturning a response to the user submitting the query from the remotecomputer.
 10. The method of claim 9, wherein the query is submitted froman application or software program on the mobile phone or other portableelectronic device.
 11. The method of claim 9, wherein the query issubmitted from a computer.
 12. A method of claim 9, wherein the returnedresponse is received by an application or software running on the mobilephone or other portable electronic device comprises a plurality of rapiddiagnostic test results of a pathological condition over at least one ofan extended geographical area or time period.
 13. The method of claim12, wherein the rapid diagnostic test results comprise datacorresponding to quantification of response, detection, or sensinglevel.
 14. The method of claim 12, wherein the rapid diagnostic testresults comprise an image.